In the integrated circuit manufacturing process, integrated circuit devices, such as transistors, are first formed at the surface of a semiconductor substrate in a wafer. An interconnect structure is then formed over the integrated circuit devices. Metal pads are formed over, and are electrically coupled to, the interconnect structure. A passivation layer and a first polymer layer are formed on the metal pads, with the metal pads exposed through the openings in the passivation layer and the first polymer layer. A Post-Passivation Interconnect (PPI) structure is then formed, which includes redistribution lines connected to the metal pads. A second polymer layer is then formed over the PPI. Under-Bump-Metallurgies (UBMs) are formed to extend into the openings in the second polymer layer, wherein the UBMs are electrically connected to the PPI. Solder balls are then placed over the UBMs and reflowed.